Pcracarida — • Tanaidacea, Isopoda. 



41 



The Tanaidacea, which are all marine, and generally of very Table-case 

 small size, are of great interest as preserving, along with the 

 Cumacea, links of connection between the stalk- eyed or " pod- 

 ophthalmate " type of the Mysidacea and the sessile-eyed or 

 " edriophthalmate " Isopoda and Amphipoda. 



Order 4.— Isopoda. 



There is no distinct carapace. As a rule, only the first 

 thoracic somite is fused with the head, and the other seven are 



Fu.. -l-l. 



B((thyiiu)ini>^ <jujanteui<, aljout oue-half natural size. (From Lankester's 

 " Treatise on Zoologv," after Milne-PMwards and Bouvier.) [Table-case 

 No. 6.J 



tree. Theie are no exopodites on the thoracic Uuil)s. The eyes, 

 when present, are sessile. Tlie ])ody is iis;ially flattened from 

 al)0ve downwards. The abdominal appendages are lamellar and 

 respiratory. 



